Crown prosecutor Brent Stanaway address the court during the trial of Helen Elizabeth Milner, a 50-year-old woman on trial in the High Court in Christchurch, Crown alleges she drugged and probably suffocated her husband and claimed he had committed suicide.

Justice David Gendall addresses the court during the trial of Helen Elizabeth Milner, a 50-year-old woman on trial in the High Court in Christchurch, Crown alleges she drugged and probably suffocated her husband and claimed he had committed suicide.

A jury deliberating on the fate of murder accused Helen Milner has adjourned for the night.

The jury retired to consider the verdict at about 11.05am when the judge finished summing up.

Justice David Gendall said the Crown claimed to have a strong circumstantial case against Milner, while the defence said it was impossible to be sure that the charges against her could be proved beyond reasonable doubt.

Judge Gendall was summing up on the 13th day of the trial of 50-year-old Milner in the High Court at Christchurch where she denies two charges of attempting to murder her husband Philip James Nisbet, 47, in April 2009, and of murdering him the following month.

The trial heard two weeks of Crown evidence, and defence evidence on Monday. Closing addresses by both sides were put to the jury yesterday.

The Crown alleged that she poisoned her husband with the anti-allergy and sedative drug Phenergan and then smothered him as he lay sedated in bed. It claims she then tried to make the death seem a suicide.

Crown prosecutor Brent Stanaway yesterday described some of the suicide notes claimed to have been written by Nisbet as a Mills and Boon style concoction by Milner. He said she had committed murder to collect her husband's $250,000 life insurance policy.

Defence counsel Rupert Glover said it would be "hugely dangerous to convict this woman on such an orchestrated body of tendentious evidence". He said some of the most important aspects of the evidence had been given by Milner's son and his partner - "witnesses so devoured by malice and venom that they didn't even take the trouble to make their lies consistent".

Jury members will return to their homes overnight if they do not complete their deliberations by late afternoon, and resume their discussions at the Court House tomorrow.